#include <usb.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
unsigned short IDVendor=   0x1384;		/*VID must be changed. */
unsigned short IDProduct=  0x8888;		/*PID must be changed. */

static int usbOpenDevice(usb_dev_handle **device, int idvendor, int idproduct)
{
	struct usb_bus *bus;
	struct usb_device *dev;
	usb_dev_handle *udh=NULL;
	int retp, retm,errors;
	char string[256];

	usb_init();
	usb_find_busses();
	usb_find_devices();
	for (bus = usb_busses; bus; bus = bus->next)
	{
		for (dev = bus->devices; dev; dev = dev->next)
		{
			udh=usb_open(dev);
			retp = usb_get_string_simple(udh, dev->descriptor.iProduct, string, sizeof(string));
			retm=usb_get_string_simple(udh, dev->descriptor.iManufacturer, string, sizeof(string));
			if (retp > 0 && retm > 0)
				if (idvendor==dev->descriptor.idVendor && idproduct==dev->descriptor.idProduct){ *device=udh;return errors=0;}
		}
	}
				 usb_close(udh);return errors=1;
}


int main(int argc, char **argv)
{
	usb_dev_handle *d=NULL;
	unsigned char buffer[3];
	int i, mode, ret;
	char string[256];

	if(argc <2)
	{
		printf("give the voltage value.\n");
		exit(1);
	}
	i=floor(atof(argv[1])*51) ;
 if(i>255){printf("value must be between 0 and 5V\n"); exit(1);} 
	mode=0;
usb_init();
ret=usbOpenDevice(&d, IDVendor,IDProduct);   <-- THIS ONE
if(ret!=0){printf("usbOpenDevice failed\n"); return 0;}

	ret=usb_control_msg(d, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN, mode, i, 0, (char *)buffer, sizeof(buffer), 5000);
//	printf("buffer %d \n", buffer[0]);
	return 0;
}